80 Hosain, by daylight, was even less inviting to look upon than it had seemed the night before. The street was narrow and unbelievably tortuous. It was paved with worn cobbles which sloped toward its center in the vain hope that rain would wash street-debris away. Because of its winding, it was never possible to see more than fifty feet ahead. When the building at last appeared, there was a police-car before it and a uniformed policeman on guard at the door. His neatness was in marked contrast to his squalid surroundings—but even so this section might have been a most aristocratic quarter in the times of the Byzantine Empire.
Coghlan was admitted without question. There was already an extensive process of cleaning-up under way. It smelled much less offensive than before. He went up the stairs and into the back room which was mentioned in the message he simply must have written, and simply hadn’t.
Duval sat on a campstool in one corner, more haggard than before. There were many books on the floor beside him, and one lay open in his hand. Ghalil smoked reflectively on a windowsill. The blank stone wall of the next building showed half-a-dozen feet beyond. Only the grayest and gloomiest of light came in the windows. Ghalil looked up and seemed pleased when Coghlan entered.
“I hoped you would come after the boat-trip,” he said cordially. “M. Duval and myself are still exchanging mutual assurances of our lunacy.”
“Up in the Sea of Marmora,” said Coghlan curtly, “somebody tried to kill Mannard. Since that’s supposedly a part of this affair, it may be crazy but it’s surely serious! Did Headquarters tell you about it?”
“There was no need,” said Ghalil mildly. “I was there.”
Coghlan stared.
“I have believed Mr. Mannard in danger from the beginning,” Ghalil explained apologetically. “I underestimated it, to be sure. But after you told me of the affair of last night—when even he believes he tripped—I have taken every possible precaution to guard him. So of course I went on the yacht.”
Coghlan said incredulously, “I didn’t see you!”
“It was stifling below-decks,” said Ghalil wryly. “But most of the sailors were my men. You must have noticed that they were not skilled seamen?”
Coghlan found all his ideas churned up again.
“But—”
“He was in no danger from the bullet,” Ghalil assured him. “I was concerned about the luncheon. In Istanbul when we think of an impending murder we think not only of knives and guns, but of poison. I took great pains against poison. The cook on the yacht tasted every item served, and he has a talent for detecting the most minute trace of the commoner poisons. An odd talent to have, eh?”
“But Mannard was shot at?” protested Coghlan.
Lieutenant Ghalil nodded. He puffed tranquilly on his cigarette.
“I am an excellent marksman,” he said modestly. “I watched. At the last possible instant—and I am ashamed to say only by accident—it was discovered that his coffee was poisoned.”
Coghlan found suspicion and bewilderment battling for primacy in his mind.
“You recall,” said Ghalil carefully, “that Mr. Mannard talked absorbedly and at length. When he went to drink his coffee, he found it cold. He sent his cup to be refilled. I am disturbed,” he interjected vexedly, “because only by accident he is alive! The cook—my talented man—poured aside the cooled coffee and refilled Mr. Mannard’s cup. And he has a fondness for tepid coffee, which I find strange. He went to drink the coffee Mr. Mannard had returned—and something had been added to it. More might remain in the cup. He told me instantly. There was no time to send a message. Mr. Mannard already had the cup in his hand. There was need for spectacular action. And I was watching the dinner-party, prepared to intervene in case of such need. I am an excellent marksman and there was nothing else to do, so I shot the cup from his hand.”
Coghlan opened his mouth, managed to close it again. “You—shot the cup . . . Who tried to poison him?”
Ghalil pulled a small glass bottle from his pocket. It was unstoppered, but there was a film of tiny crystals in it as if some liquid had dried.
“This,” he observed, “fell from your pocket as you hunted in the brushwood for the marksman who actually was on the yacht. One of my men saw it fall and brought it to me. It is poison.”
Coghlan looked at the bottle.
“I’m getting a little bit fed up with mystification. Do I get arrested?”
“The fingerprints upon it are smudged,” said Ghalil. “But I am familiar with your fingerprints. They are not yours. It was slipped into your pocket—not fully, therefore it fell out. You do not get arrested.”
“Thank you,” said Coghlan with irony.
His foot pushed aside one of the books on the floor beside Duval. They were of all sizes and thickness, and all were modern. Some had the heavy look of German technical books, and one or two were French. The greater number were in modern Greek.
“M. Duval searches history for references which might apply to our problem,” said the Turk. “I consider this a very important affair. That, in particular—” he pointed to the wet spot on the wall—”seems to me most significant. I am very glad that you came here, with your special knowledge.”
“Why? What do you want me to do?”
“Examine it,” said Ghalil. “Explain it. Let me understand what it means. I have a wholly unreasonable suspicion I would not like to name, because it has only a logical basis.”
“If you can make even a logical pattern out of this mess,” said Coghlan bitterly, “you’re a better man than I am. It simply doesn’t make sense!”
Ghalil only looked at him expectantly. Coghlan went to the wet spot. It was almost exactly square, and there was no trace of moisture above it or on either side. Some few trickles dripped down from it, but the real wetness was specifically rectangular. Coghlan felt the wall about it. Everywhere except in the wet spot the wall had the normal temperature of a plaster coating. The change of temperature was exactly what would have been apparent if a square-shaped freezing unit had been built into the structure. The plaster was rotten from long soaking. Coghlan took out a pocket-knife and dug carefully into it.
“What rational connection can this have with that stuff in the book, and with somebody trying to kill Mannard?” he demanded as he worked.
“No rational connection,” admitted Ghalil. “A logical one. In police work one uses reason oneself, but does not expect it of events.”
An irregularly shaped patch of wetted plaster cracked and came away. Coghlan looked at it and started.
“Ice!” he said sharply. “There must be some machinery here!”
The space from which the plaster had come was white with frost. Coghlan scraped at it. A thin layer of ice, infinitesimally thin. Then more wet plaster, which was not frozen. Coghlan frowned. First ice, then no ice—and nothing to make the ice where the ice was. A freezing coil could not work that way. Coldness does not occur in layers or in thin sheets. It simply does not.
Coghlan dug angrily, stabbing with the point of the knife. The knife grew very cold. He wrapped his handkerchief about it and continued to dig. There was wetness and rotted plaster for another inch. Then the heavy stone wall of the building.
“The devil!” he said angrily. He stood back and stared at the opening.
There was silence. He had made a hole through rotted plaster, bind found nothing but a thin layer of ice, and then more rotted plaster. He looked at it blankly. Then he saw that though the frost had been cut away, there was a slight mist in the opening he had made. He blew his breath into the hole. He made an astonished noise.